1. Field of the Invention
The present invention relates to a strength reinforcing structure of a lock outer handle, and more particularly to a lock having a circular handle or flat handle, wherein the strength of the lock can be enhanced.
2. Description of the Related Prior Art
A conventional lock in accordance with the prior art shown in FIG. 10 comprises an axial tube 91 combined with a restoring plate 92 which defines a square hole 921 for passage of a drive shaft 93. By rotation of the handle 95, the drive shaft 93 drives a lock latch to drive a drive wheel to rotate, thereby pulling the lock tongue of the lock latch to extend or retract. The restoring plate 92 is provided with protrusions 922 rested on the fixing tubes 94 of the inner and outer handle sets for limiting the rotation angle of the handle 95. When locked, the drive plate 96 is rotated to move a lock snapping plate 97 in a positioning slot 99 to enter a stop chute 98, whereby the lock snapping plate 97 is locked in the stop chute 98, so that the drive shaft tube 91 cannot be rotated by rotating the handle 95 without a correct key.
If the handle is rotated when the lock is locked, the force from the handle is transmitted to the axial tube 91 whose positioning slot 99 together with the lock snapping plate 97 is used to support the entire breaking force. When the force reaches a determined extent, the positioning slot 99 will be broken, so that the axial tube 91 can be rotated to unlock the lock. In addition, when the lock is at an unlocked state, the user generally rotate the handle to the maximum to open the door, so that the combination position of the restoring plate 92 and the axial tube 91 supports a larger force and is easily worn out during a long-term utilization, thereby forming an idle gap when the handle 95 is rotated. Further, the restoring plate 92 is provided with protrusions 922 rested on the fixing tubes 94 of the inner and outer handle sets for limiting the rotation angle of the handle 95, so that the protrusions 922 are easily worn out during a long-term utilization.
The primary objective of the present invention is to provide a strength reinforcing structure of a lock outer handle, having a greater strength, so that the lock can be used during a long-term utilization.
In accordance with the present invention, there is provided a strength reinforcing structure of a lock outer handle including a disk seat defining a first hole in which a handle and a drive shaft tube are rotatably mounted. The handle is provided with a drive plate that is driven by a lock core to rotate, and may drive a lock snapping plate to move along a longitudinal direction thereof. The drive shaft tube has one end secured in the handle, the drive shaft tube receives an elastic member and a stop plate therein and defines a positioning slot for allowing protrusion of the lock snapping plate, and the other end of the drive shaft tube is provided with locking grooves in which the locking blocks of a driven ring is locked. The driven ring is combined with a drive tube which is combined with a restoring member. The restoring member defines fitting slots combined on end edges of the drive shaft tube, and the restoring member includes a restoring element mounted thereon. The drive tube also passes through a positioning plate which defines openings locked on the positioning tubes of the disk seat. The positioning plate has a center defining a second hole which has an inner wall provided with locking edges for allowing engagement or disengagement of end edges of the lock snapping plate. The second hole of the positioning plate is additionally provided with stop protrusions protruding toward the center there.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.